Food Chain Magnate - Restaurant (Clean-up Fix)

A fix to the restaurant tile from [Food Chain Magnate Game Pieces by darhf](http://www.thingiverse.com/thing:1084086).

List of fixes made:

1. Added a 45° stoop underneath the roof's gutter, which is to prevent the gutter portion to be printed in thin air
2. Added the thickness of the sign on top of the roof and give it more support. This makes is more sturdy and less likely to get snapped off accidentally.